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A Collado

Publications and source records attributed to A Collado.

At least 19 recordsLinked to original sources
PubMed2005

Immunohistochemical expression of Ki-67 antigen, cox-2 and Bax/Bcl-2 in prostate cancer; prognostic value in biopsies and radical prostatectomy specimens.

PURPOSES: To elucidate the prognostic value of the immunohistochemical (IHC) expression of Bcl-2, Bax, Cox-2 and Ki-67 antigen in biopsy cores (C) and surgical specimens (SP) of prostate cancer (PC) and to determine the C to SP reproducibility. MATERIAL AND METHODS: The IHC study was carried out in 91 patients operated by means of radical prostatectomy (RP) with available formalin-fixed paraffin-embedded material from both C and SP. RESULTS: The IHC expression of Bcl-2 in C and SP was very low (5%). Bax was expressed in almost all the patients and did not show any prognostic value. We observed a good reproducibility between C and SP for all molecules except with Bax. In prostate C, Ki-67 and Cox-2 were considered positive in 42.9% and 67% of the patients respectively, and were related to disease-free survival in the univariate analysis. The expression of these two markers in SP was observed in 51.6% and 79.1% of the patients and the expression of Ki-67 in SP maintained its independence as prognostic factor in the multivariate analysis related to disease-free survival. CONCLUSIONS: The IHC expression of Ki-67 and Cox-2 proteins in our study do offer valuable prognostic information, mostly the first one. Thus, we think these markers might be studied in larger series of patients for its further validation as prognostic factors in prostate biopsies.

Aged↗
PubMed2005

Bladder blood flow and de-obstructive open prostatectomy: correlation with clinical and urodynamic parameters.

PURPOSE: To assess the relation between tissue blood flow changes during surgery with clinical and urodynamic parameters in obstructed patients. MATERIAL AND METHODS: A prospective study was conducted in 18 symptomatic patients with bladder outlet obstruction undergoing retropubic prostatectomy. A symptom assessment and a preoperative urodynamic study were performed. To measure bladder blood flow a BLF-10 laser Doppler flowmeter and a blunt-tipped probe were used intraoperatively. Tissue flow was measured in TPU units (1 TPU unit=1 ml per minute per 100 mg of tissue). Six measurements were taken: two control in the rectus abdominis muscle and four in the detrusor, two before the incision of the prostatic capsule and two after closure. For the statistical analysis, Wilcoxon test and a regression analysis were performed. RESULTS: Mean age was 70 years (range: 56-84). Six patients had an episode of acute urinary retention (AUR). No differences were found in the initial and final values of bladder blood flow of the rectus muscle and the bladder dome. A decrease of bladder blood flow in the anterior bladder wall was observed after prostate enucleation. AUR patients showed no differences in bladder blood flow values. Bladder blood flow (BBF) changes showed no correlation with any urodynamic or clinical parameter. CONCLUSIONS: Laser Doppler flowmetry is useful to study BBF with low morbidity, ease of use and reproducibility. Following de-obstructive surgery, a decrease in BBF occurs, probably associated with surgery. These changes are similar in patients with and without AUR and show no correlation with other parameters studied.

Aged↗
PubMed2003

Tumour immunology, vaccination and escape strategies.

Our increasing knowledge of the mechanisms by which tumour cells escape immune effector cells is helping to establish new approaches to therapeutic vaccination against tumour development. One of the escape mechanisms used by tumour cells is the generation of multiple variants with different HLA phenotypes. These MHC class I phenotypic alterations play a key role in the tumour-host scenario, as they are crucial molecules for antigen presentation to T cells and modulation of natural killer (NK) cell activity. This review presents evidence indicating that tumours develop sophisticated MHC phenotypes that allow them to escape immune surveillance. We evaluate the importance of these alterations in terms of the potential development of therapeutic approaches to immune vaccination.

Animals↗
PubMed2002

Usefulness of sputum culture for diagnosis of bacterial pneumonia in HIV-infected patients.

The use of sputum culture in immunocompetent patients with community-acquired pneumonia is controversial. The usefulness of this technique in HIV-infected patients has not been evaluated. A prospective, observational, multicenter, hospital-based study of bacterial community-acquired pneumonia was carried out to analyze the value of sputum culture in HIV-infected patients. Only good-quality sputum samples were cultured. Altogether, 355 cases of bacterial community-acquired pneumonia were included. An etiological diagnosis was obtained in 190 (53.5%) cases. Sputum was cultured in 313 (88.1%) cases, being diagnostic in 108 (34.5%). The microorganism identified in sputum culture was the same as that identified in sterile samples in 26 of 27 (96.3%) cases in which both cultures were diagnostic. The microbiologic findings in sputum and bronchoscopic cultures were concordant in seven of eight (87.5%) cases in which both were positive. These results suggest that sputum culture is a useful technique, given its availability and ease of performance and its good correlation with culture of sterile samples.

AIDS-Related Opportunistic Infections↗
PubMed2001

Prostatic abscess due to Candida with no systemic manifestations.

Prostatic abscess due to fungi is a rare condition. It is generally secondary to systemic disease in immunosuppressed patients. It usually occurs with affection of other organs in a septic patient. Only in exceptional cases does it occur isolatedly. We present the case of a prostatic abscess due to Candida albicans with no systemic manifestations. The diagnosis is helped by transrectal ultrasound, which allows to differentiate this condition from nonabscessed acute prostatitis. The treatment of choice is ultrasound-guided transrectal needle aspiration after antibiotic therapy has been started. As with abscesses of bacterial origin, an ultrasonographic follow-up is required due to the possibility of persistence or recurrence.

Abscess↗
PubMed2000

Molecular strategies to define HLA haplotype loss in microdissected tumor cells.

Loss of heterozygosity (LOH) of chromosome 6p21 is an important mechanism that generates HLA haplotype loss in various human tumors. This mechanism produces non-reversible HLA-deficient tumor cells that can escape T cell immune responses in peptide-vaccinated cancer patients. However, the exact frequency of this mechanism is still unknown, because contaminating stroma in solid tumor tissues masks the tumor DNA obtained from solid samples. A microdissection technique was applied to 4-8 microm sections of cryopreserved tumor tissues from a group of colorectal and laryngeal carcinomas. Fifteen patients were analyzed for the presence of LOH associated with the beta(2)-microglobulin gene in chromosome 15, and five patients for LOH associated with HLA genes in chromosome 6. In two cases, autologous metastasis tissue samples were also available. The patients were selected for showing an altered HLA class I tumor phenotype as determined by immunohistological techniques. DNA was obtained from this microdissected material and amplified in order to detect the presence or absence of nine previously selected microsatellite markers. HLA sequence based typing (SBT) was also applied to these microdissected DNA samples to define the HLA genotype. Microdissection greatly improved the definition of LOH, with nearly 100% signal reduction in one of the alleles. In addition, this procedure allowed us to detect beta(2)-microglobulin LOH in tumors that expressed some HLA molecules. Our data indicate that this procedure can be successfully applied to microdissected samples from solid tumors, thus enhancing the power and sensitivity of LOH detection.

Colorectal Neoplasms↗
PubMed2000

Criteria to define HLA haplotype loss in human solid tumors.

Short tandem repeat (STR) markers are currently used to define loss of heterozygosity (LOH) of genes and chromosomes in tumors. Chromosome 6 and chromosome 15 STR markers are applied to define loss of HLA and related genes (e.g. TAP and beta2m). The number of STR identified in the HLA region is still increasing. In this study, seven representative STR markers covering the 6p/6q arms of chromosome 6 including the HLA region and two for chromosome 15 flanking the beta2m gene, were selected as minimally required for reliable LOH studies. A multiplex polymerase chain reaction (PCR) strategy is proposed when small number of cells are available in microdissected tumor samples.

Biomarkers, Tumor↗
PubMed2000

Clear cell adenocarcinoma in a female urethral diverticulum.

The incidence of a neoplasm within the female urethral diverticulum is rare. Clear cell adenocarcinoma, which is the most common neoplasm, arises from the metaplasia of surface transitional epithelium and the paraurethral ducts. These tumors are usually diagnosed at a late stage, which worsens their prognosis. The treatment of choice is surgery.

Adenocarcinoma, Clear Cell↗
PubMed2000

Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

Although Haemophilus influenzae is a common etiologic agent of pneumonia in patients infected with human immunodeficiency virus (HIV), the characteristics of this pneumonia have not been adequately assessed. We have prospectively studied features of H. influenzae pneumonia in 26 consecutive HIV-infected inpatients. Most of these patients were severely immunosuppressed; 73.1% had a CD4+ cell count <100/microL. A subacute clinical presentation was observed in 27% of the patients and was associated with a higher degree of immunosuppression (P=.04). Bilateral lung infiltrates were noted radiographically in 57.7% of the cases. The mortality attributable to H. influenzae pneumonia was 11.5%. Thus, pneumonia caused by H. influenzae affects mainly patients with advanced HIV disease, and since its clinical and radiological features may be diverse, this etiology should be considered when pneumonia occurs in patients with advanced HIV infection. The mortality rate associated with H. influenzae pneumonia is not higher than that occurring in the general population.

AIDS-Related Opportunistic Infections↗
PubMed2000

Community-acquired bacterial pneumonia in human immunodeficiency virus-infected patients: validation of severity criteria. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

Severity criteria for community-acquired pneumonia (CAP) have always excluded patients with human immunodeficiency virus (HIV) infection. A 1-yr, multicenter, prospective observational study of HIV-infected patients with bacterial CAP was done to validate the criteria used in the American Thoracic Society (ATS) guidelines for CAP, and to determine the prognosis-associated factors in the HIV-infected population with bacterial CAP. Overall, 355 cases were included, with an attributable mortality of 9.3%. Patients who met the ATS criteria had a longer hospital stay (p = 0.01), longer duration of fever (p < 0.001), and higher attributable mortality (13.1% versus 3.5%, p = 0.02) than those who did not. Three factors were independently related to mortality: CD4(+) cell count < 100/microl, radiologic progression of disease, and shock. Pleural effusion, cavities, and/or multilobar infiltrates at admission were independently associated with radiologic progression. A prognostic rule based on the five criteria of shock, CD4(+) cell count < 100/microl, pleural effusion, cavities, and multilobar infiltrates had a high negative predictive value for mortality (97.1%). The attributable mortality for severe pneumonia was 11.3%, as compared with 1.3% for nonsevere disease (p = 0.008). The ATS severity criteria are valid in HIV-infected patients with bacterial CAP. Our study provides the basis for identification of patients who may require hospitalization determined by clinical judgment and the five clinical criteria of shock, a CD4(+) cell count < 100/microl, pleural effusion, cavities, and multilobar involvement. These prognostic factors should be validated in independent cohort studies.

AIDS-Related Opportunistic Infections↗
PubMed2000

Management of superficial transitional cell carcinoma in the intramural ureter: what to do?

PURPOSE: We analyze the evolution of superficial transitional cell carcinoma in the intramural distal ureter treated with transurethral resection. MATERIALS AND METHODS: A total of 19 patients underwent transurethral resection of the intramural distal ureter with a mean followup of 57 months. All cases were diagnosed as superficial transitional cell carcinoma and all but 2 had a history of bladder tumor. Upper urinary tract followup consisted of excretory urography every 6 months and ureterorenoscopy in cases with a doubtful diagnosis or positive cytology. RESULTS: Pathological examination revealed stage Ta disease in 42%, T1 in 31.5% and Tx in 26.3% of intramural tumors. Upper urinary tract recurrence was noted in 8 patients (42.1%), including 5 (62.5%) with involvement of the distal ureter. Nontumoral stenosis of the distal ureter in 3 cases was treated endoscopically. An endoscopic procedure resolved 75% of recurrences. A high surgical risk patient who did not undergo open surgery died of recurrence. CONCLUSIONS: Superficial transitional cell carcinoma of the intramural ureter is uncommon in the setting of multiple bladder tumors and recurrent bladder carcinoma. There was a 42.1% rate of ipsilateral recurrence and endoscopic treatment allowed us to preserve 89.5% of the involved renal units. Closer followup of the urinary tract must be performed since these tumors have a higher incidence of upper urinary tract recurrence.

Aged↗
PubMed2000

Early complications of endoscopic treatment for superficial bladder tumors.

PURPOSE: Bladder tumors are the second most common tumors of the genitourinary system. Approximately 80% of patients initially present with a superficial lesion, which is treated with transurethral resection. Although transurethral resection is a standard procedure, it is not morbidity-free. We assessed the early complications of transurethral resection for superficial bladder cancer and analyzed various factors that may contribute to its occurrence. MATERIALS AND METHODS: Between January 1979 and December 1996, 2,821 patients with superficial bladder cancer underwent transurethral resection at our center. We assessed intraoperative and immediate postoperative complications of the initial transurethral resection procedure, and correlated them with tumor characteristics. RESULTS: Of the 2,821 patients in our study 2,461 (87%) were male and 360 (13%) were female. Average age was 65 years (range 16 to 94). Of the 145 complications (5.1%) the most common were bleeding in 78 patients (2.8%) and bladder perforation in 36 (1. 3%). Perforation was extraperitoneal in 30 cases (83%) and intraperitoneal in 6 (17%). Conservative treatment and open surgery were done in 32 (89%) and 4 (11%) patients, respectively. We noted no case of tumor seeding. A repeat procedure was done in 77 patients (2.7%) with bleeding as the leading cause of repeat intervention in 65 (84%). Blood transfusion was required in 96 cases (3.4%). The incidence of complications significantly correlated with the size and number of tumors but there was no association with tumor stage, grade or location. CONCLUSIONS: The most common complication of transurethral resection for superficial bladder cancer is bleeding. Currently bladder perforation should be managed conservatively with a minimum risk of extravesical tumor seeding. Our results imply that tumor size and multiple tumor resection are associated with a higher complication rate.

Adolescent↗
PubMed1999

Chromosome loss is the most frequent mechanism contributing to HLA haplotype loss in human tumors.

Loss of heterozygosity (LOH) in the short arm of chromosome 6 (6p) was detected in samples obtained from colon (13.8%), larynx (17.6%) and melanoma (15.3%) tumors. The parallel study of HLA-antigen expression in tumor tissues using locus- and polymorphic-specific antibodies in combination with LOH microsatellite analysis on 6p allowed us to establish that LOH in chromosome 6 is a representative phenomenon in most tumor cells present in a given tumor tissue. In most cases, specific HLA alleles had been lost in a predominant population of tumor cells, indicating that LOH is a non-irrelevant mutation that probably confers a selective advantage for survival of the mutant cell. We also demonstrate that LOH frequently occurred through chromosome loss rather than somatic recombination. LOH at all loci studied on the p and q arms of chromosome 6 was observed in at least 56.2% (9/17) cases. This HLA-associated microsatellite analysis was a useful tool for classifying tumors as LOH-positive or -negative, and therefore to consider a patient as a potential non-responder or responder in a vaccination trial.

Antibodies, Monoclonal↗
PubMed1999

Expression of HLA G in human tumors is not a frequent event.

Expression of HLA G may be a way for tumor cells to escape immuno-surveillance. HLA G is selectively expressed by extravillous trophoblast in the human placenta, a tissue that does not express HLA A or B molecules. It is tempting to propose that tumor cells resemble this unique HLA class I phenotype as they frequently lose classical HLA A, B and C class I expression. Such peculiar HLA class I distribution would in theory allow tumor cells to escape from T- and NK-cell cytotoxicity. To determine whether HLA G is expressed on tumor cells, we studied HLA G mRNA levels using RT-PCR and HLA G cell-surface expression by immunohistological techniques in a panel of 50 human solid tumor tissues, 31 tumor cell lines of different origin, 4 autologous mucosa samples and 3 peripheral white cell samples. We found mRNA transcripts of different HLA G isoforms in most of the samples studied. However, we did not detect cell-surface expression of HLA G using 3 specific monoclonal antibodies (MAbs; 87G, 01G and G223). HLA G was detected only in the U937 myelomonocytic cell line after stimulation with IFN-gamma. We favor the hypothesis that HLA G plays a minor role, if any, in providing an inhibitory signal to NK cells to escape immunosurveillance. We cannot, however, exclude the possibility that some other HLA G isoforms may be expressed in some tumors.

Antibodies, Monoclonal↗
PubMed1999

Significant loss of bone mass in patients with early, active ankylosing spondylitis: a followup study.

OBJECTIVE: To analyze whether inflammatory disease activity plays a substantial role in the loss of bone mass observed in ankylosing spondylitis (AS) patients who have not yet developed ankylosis. METHODS: A longitudinal cohort study of 34 patients with early AS (duration <10 years) without ankylosis was conducted. The mean followup was 19 months. Loss of bone mass in defined regions of the lumbar spine and femoral neck was analyzed by dual x-ray absorptiometry. Patients were grouped according to biologic parameters of disease activity (erythrocyte sedimentation rate or C-reactive protein level). Group 1 consisted of 14 patients with active disease; group 2 comprised 20 patients with inactive disease. Serum levels of interleukin-6 (IL-6) and of hormones (sex, thyroid, and calciotropic), vertebral mobility (Schober test), daily physical activity, and treatment administered were recorded every 6 months for all patients. RESULTS: At the end of the followup period, patients with active AS showed a significant reduction in bone mass in the lumbar spine (mean 1.01 gm/cm2 at study entry versus 0.961 gm/cm2 at followup [P = 0.005]) and femoral neck (0.849 gm/cm2 versus 0.821 gm/cm2 [P = 0.015]), which represented losses of 5% and 3%, respectively. In contrast, no significant reduction in bone mass was observed in patients with inactive AS. As expected, serum IL-6 levels were significantly higher in patients with active AS than in those with inactive disease (mean +/- SD 8.3 +/- 9 pg/ml versus 2.8 +/- 5 pg/ml [P = 0.008]). No significant differences were observed between the 2 groups in any of the other variables analyzed. CONCLUSION: The observation that loss of bone mass in AS occurred only in patients with persistent active disease strongly suggests that inflammatory activity of the disease itself plays a major role in the pathophysiology of the early bone mineral disorders observed in these patients.

Adult↗